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Endothall
CASRN 145-73-3
Contents
0155
Endothall; CASRN 145-73-3
Health assessment information on a chemical substance is included in IRIS only
after a comprehensive review of chronic toxicity data by U.S. EPA health
scientists from several Program Offices and the Office of Research and
Development. The summaries presented in Sections I and II represent a
consensus reached in the review process. Background information and
explanations of the methods used to derive the values given in IRIS are
provided in the Background Documents.
STATUS OF DATA FOR Endothall
File On-Line 03/31/1987
Category (section) Status Last Revised
----------------------------------------- -------- ------------
Oral RfD Assessment (I.A.) on-line 03/01/1991
Inhalation RfC Assessment (I.B.) no data
Carcinogenicity Assessment (II.) no data 09/01/1991
_I. CHRONIC HEALTH HAZARD ASSESSMENTS FOR NONCARCINOGENIC EFFECTS
__I.A. REFERENCE DOSE FOR CHRONIC ORAL EXPOSURE (RfD)
Substance Name -- Endothall
CASRN -- 145-73-3
Last Revised -- 03/01/1991
The oral Reference Dose (RfD) is based on the assumption that thresholds exist
for certain toxic effects such as cellular necrosis. It is expressed in units
of mg/kg-day. In general, the RfD is an estimate (with uncertainty spanning
perhaps an order of magnitude) of a daily exposure to the human population
(including sensitive subgroups) that is likely to be without an appreciable
risk of deleterious effects during a lifetime. Please refer to the Background
Document for an elaboration of these concepts. RfDs can also be derived for
the noncarcinogenic health effects of substances that are also carcinogens.
Therefore, it is essential to refer to other sources of information concerning
the carcinogenicity of this substance. If the U.S. EPA has evaluated this
substance for potential human carcinogenicity, a summary of that evaluation
will be contained in Section II of this file.
___I.A.1. ORAL RfD SUMMARY
Critical Effect Experimental Doses* UF MF RfD
-------------------- ----------------------- ----- --- ---------
Increased absolute NOEL: 100 ppm (diet) 100 1 2E-2
and relative weights (2 mg/kg bw/day) mg/kg/day
of stomach and small
intestine LEL: 300 ppm (diet)
(6 mg/kg bw/day)
Two-Year Feeding
Study in Dogs
Pennwalt Agchem., 1965
*Dose Conversion Factors & Assumptions: Dose adjusted for assumed dog
food consumption (2.5% bw/day) and expressed as endothall ion.
___I.A.2. PRINCIPAL AND SUPPORTING STUDIES (ORAL RfD)
Pennwalt Agchem. 1965. MRID No. 00101735. Available from EPA. Write to
FOI, EPA, Washington, DC 20460.
Three male and 3 female dogs were administered diets that initially contained
0, 100, 300 or 800 ppm of disodium endothall. The concentration in the high-
dose group was gradually increased over months 19-22 to a final concentration
of 2000 ppm. The doses were calculated on the basis of the amount of
endothall ion in the diet, and the standard equivalence factor for dogs (0.025
kg of diet/kg of bw/day). No effect on weight gain, hematology, BSP
clearance, SGOT or urinalysis was noted. At necropsy, increased absolute and
relative weights of stomach and small intestine were noted in intermediate and
high-dose dogs. Increased "mucosal gland activity" was noted in the stomachs
of high-dose dogs, along with slight edema of the pyloric region.
___I.A.3. UNCERTAINTY AND MODIFYING FACTORS (ORAL RfD)
UF -- An uncertainty factor of 100 was used to account for inter- and
intraspecies differences.
MF -- None
___I.A.4. ADDITIONAL COMMENTS (ORAL RfD)
Data Considered for Establishing the RfD:
1) Two-Year Feeding - dog: Principal study - see previous description; no
core grade
2) 3-Generation Reproduction - rat: NOEL=100 ppm (5 mg/kg/day); LEL=2500 ppm
(125 mg/kg/day) [weight loss, kidney and adrenal discoloration, F2B pup
mortality (dose discontinued)]; core grade minimum (Pennwalt Corp., 1965)
3) 2-Year Feeding (oncogenic) - rat: Systemic NOEL=2500 ppm (125 mg/kg/day)
(HDT); no core grade (only 10 animals/sex were used) (Pennwalt Corp., 1977)
4) Teratology with postnatal phase - rat: Maternal NOEL=10 mg/kg/day;
Maternal LEL=20 mg/kg/day (death); Fetotoxic NOEL=10\mg/kg/day; Fetotoxic
LEL=40 mg/kg/day (increased number of skeletal variations); core grade minimum
(Pennwalt Corp., 1982)
5) Teratology - mouse: Teratogenic NOEL=20 mg/kg/day; Teratogenic LEL= 40
mg/kg/day (HDT) (skeletal malformations noted at HDT with maternal toxicity);
Maternal NOEL=5 mg/kg/day; Maternal LEL=20\mg/kg/day (death); Fetotoxic
NOEL=20 mg/kg/day; Fetotoxic LEL=40\mg/kg/day (skeletal anomalies); core grade
minimum (Pennwalt Corp., 1981)
6) 6-Week Feeding - dog: NOEL=10 mg/kg/day; LEL=20\mg/kg/day (100% mortality
at this dose level and higher; congested and edematous stomachs with
occasional erosion and hemorrhage); no core grade (Pennwalt Corp., 1953)
Data Gap(s): Chronic Rat Feeding Study (repeat study in progress)
___I.A.5. CONFIDENCE IN THE ORAL RfD
Study -- Medium
Data Base -- Medium
RfD -- Medium
The critical study appears to be of fair quality and is given a medium
confidence rating. The data base is generally supportive but since there is a
data gap existing for endothall, the data base is also given a medium
confidence rating. Medium confidence in the RfD follows.
___I.A.6. EPA DOCUMENTATION AND REVIEW OF THE ORAL RfD
Pesticide Registration Files
Agency Work Group Review -- 04/22/1986, 11/25/1986
Verification Date -- 11/25/1986
___I.A.7. EPA CONTACTS (ORAL RfD)
Please contact the Risk Information Hotline for all questions concerning this
assessment or IRIS, in general, at (513)569-7254 (phone), (513)569-7159 (FAX)
or RIH.IRIS@EPAMAIL.EPA.GOV (internet address).
__I.B. REFERENCE CONCENTRATION FOR CHRONIC INHALATION EXPOSURE (RfC)
Substance Name -- Endothall
CASRN -- 145-73-3
Not available at this time.
_II. CARCINOGENICITY ASSESSMENT FOR LIFETIME EXPOSURE
Substance Name -- Endothall
CASRN -- 145-73-3
Not available at this time.
_VI. BIBLIOGRAPHY
Substance Name -- Endothall
CASRN -- 145-73-3
Last Revised -- 07/01/1992
__VI.A. ORAL RfD REFERENCES
Pennwalt Agchem. 1965. MRID No. 00101735. Available from EPA. Write to
FOI, EPA, Washington, DC 20460.
Pennwalt Corporation. 1953. MRID No. 00040962. Available from EPA. Write
to FOI, EPA, Washington, DC 20460.
Pennwalt Corporation. 1965. MRID No. 00084610. Available from EPA. Write
to FOI, EPA, Washington, DC 20460.
Pennwalt Corporation. 1977. MRID No. 00084609. Available from EPA. Write
to FOI, EPA, Washington, DC 20460.
Pennwalt Corporation. 1981. MRID No. 00073371, 00085940. Available from
EPA. Write to FOI, EPA, Washington, DC 20460.
Pennwalt Corporation. 1982. MRID No. 00118952. Available from EPA. Write
to FOI, EPA, Washington, DC 20460.
__VI.B. INHALATION RfC REFERENCES
None
__VI.C. CARCINOGENICITY ASSESSMENT REFERENCES
None
_VII. REVISION HISTORY
Substance Name -- Endothall
CASRN -- 145-73-3
-------- -------- --------------------------------------------------------
Date Section Description
-------- -------- --------------------------------------------------------
03/01/1991 I.A.4. Citations added
03/01/1991 VI. Bibliography on-line
09/01/1991 II. Carcinogenicity assessment now under review
01/01/1992 IV. Regulatory Action section on-line
07/01/1992 III.A. Health Advisory on-line
07/01/1992 VI.D. Health Advisory references on-line
08/01/1992 III.A.5. Text clarified
VIII. SYNONYMS
Substance Name -- Endothall
CASRN -- 145-73-3
Last Revised -- 03/31/1987
145-73-3
AQUATHOL
1,2-CYCLOHEXANEDICARBOXYLIC ACID, 3,6-endo-EPOXY-
3,6-ENDOOXOHEXAHYDROPHTHALIC ACID
ENDOTHAL
Endothall
ENDOTHAL TECHNICAL
3,6-ENDOXOHEXAHYDROPHTHALIC ACID
HYDOUT
HYDROTHAL-191
HYDROTHAL-47
7-OXABICYCLO(2.2.1)HEPTANE-2,3-DICARBOXYLIC ACID
PHTHALIC ACID, HEXAHYDRO-3,6-endo-OXY-
RCRA WASTE NUMBER P088
TRI-ENDOTHAL
Last updated: 5 May 1998
URL: http://www.epa.gov/iris/SUBST/0155.HTM
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